JPWO2020170720A1 - Flow control valve and its assembly method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow rate control valve capable of effectively reducing a differential pressure applied in a moving direction with respect to a valve body without restricting the shape of the valve body, and an assembling method thereof.
SOLUTION: In a flow control valve 1, a lower end 20a of an outer cylinder member 20 is closed by a base member 10, and an upper end 20b of the outer cylinder member 20 is closed by a holder main body 71. A partitioned back pressure chamber 23 is formed. The drive shaft 64 is arranged so as to straddle the valve chamber 13 and the back pressure chamber 23. The substrate member 10 is provided with a flow path 16 connected to the valve port 15 and a pressure equalizing hole 17 connecting the flow path 16 and the back pressure chamber 23.
[Selection diagram] Fig. 3

Description

The present invention relates to, for example, a flow rate control valve incorporated in a refrigeration cycle or the like and used for controlling the flow rate of a fluid such as a refrigerant, and a method for assembling the valve.

Patent Document 1 discloses a conventional pressure-balanced flow rate control valve. The flow control valve of Patent Document 1 has a cylindrical guide portion provided in the valve housing and a valve body slidably provided in the guide portion. The valve body opens and closes the valve opening by being moved in the axial direction (that is, the moving direction) of the guide portion by the actuator. Further, the valve body is provided with a pressure equalizing path connecting the valve port and the back pressure chamber so as to balance the pressure between the fluid pressure of the valve port and the fluid pressure of the back pressure chamber. As a result, the difference (differential pressure) between the fluid pressure applied from the valve opening side and the fluid pressure applied from the back pressure chamber side to the valve body is made small.

Japanese Unexamined Patent Publication No. 2016-211600

However, in the flow rate control valve of Patent Document 1, since the vertical hole penetrating the valve body is provided as a pressure equalizing path, the tip of the valve body cannot be formed into a sharp shape. Therefore, the shape of the valve body is restricted. As a result, for example, it becomes difficult to realize a flow rate characteristic of equal percentage, and the flow rate characteristic is also restricted.

Therefore, an object of the present invention is to provide a flow control valve capable of effectively reducing the differential pressure applied in the moving direction with respect to the valve body without restricting the shape of the valve body, and a method for assembling the flow rate control valve.

In order to achieve the above object, the flow control valve according to one aspect of the present invention includes a valve chamber, a base member provided with a valve opening opening in the valve chamber, and an outer cylinder arranged outside the base member. A member, a valve body arranged to face the valve port and open / close the valve port, a drive shaft provided with the valve body at the tip portion, and the drive shaft of the valve port and the valve body. It has a support member that movably supports in the opposite direction, one end of the outer cylinder member is closed by the base member, and the other end of the outer cylinder member is closed by the support member. A back pressure chamber partitioned from the valve chamber is formed, the valve body or the drive shaft is arranged so as to straddle the valve chamber and the back pressure chamber, and the base member is a flow path connected to the valve opening. A pressure equalizing hole for connecting the flow path and the back pressure chamber is provided.

According to the present invention, one end of the outer cylinder member is closed by the base member, and the other end of the outer cylinder member is closed by the support member, forming a back pressure chamber partitioned from the valve chamber. There is. The valve body or drive shaft is arranged so as to straddle the valve chamber and the back pressure chamber. The substrate member is provided with a flow path connected to the valve port and a pressure equalizing hole connecting the flow path and the back pressure chamber. As a result, the fluid pressure applied from the valve opening side to the valve body and the back pressure chamber side to the valve body in the valve closed state in which the valve opening is closed by the valve body by the pressure equalizing hole provided in the base member. The difference from the applied fluid pressure can be reduced. Therefore, the differential pressure applied to the valve body in the moving direction can be effectively reduced without restricting the shape of the valve body.

In the present invention, the flow rate control valve is formed in an annular shape through which the valve body or the drive shaft penetrates, and has a sealing member that seals between the valve chamber and the back pressure chamber, and the sealing. It is preferable that the diameter of the sealing portion sealed by the member is the same as the diameter of the valve port. By doing so, the difference between the fluid pressure applied from the valve opening side and the fluid pressure applied from the back pressure chamber side to the valve body can be made zero (including almost zero) in the valve closed state. Therefore, the differential pressure applied to the valve body in the moving direction can be reduced more effectively without restricting the shape of the valve body.

In the present invention, the flow control valve is provided with a protrusion on one of the base member and the support member, and the protrusion is inserted into the other in a direction orthogonal to the facing direction of the protrusion. It is preferable that a hole for restricting the movement to is provided. For example, when the base member and the support member are assembled via the outer cylinder member, the valve is affected by the dimensional tolerances and the assembly accuracy of the base member and the outer cylinder member, and the support member and the outer cylinder member, respectively. There is a risk of misalignment between the mouth and the valve body. On the other hand, one of the base member and the support member is provided with a protrusion for positioning, and the other is provided with a hole for positioning, and the base member and the support member are directly assembled to form the valve port and the valve body. The axis deviation with and can be effectively suppressed.

In the present invention, the base member is provided with a circular hole coaxially arranged with the valve port as the hole, and the support member is provided with a cylindrical portion coaxially arranged with the drive shaft as the protrusion. It is preferable that it is provided. By doing so, it is possible to effectively suppress the misalignment between the valve mouth and the valve body with a relatively simple configuration.

In the present invention, it is preferable that the cylindrical portion is press-fitted into the circular hole. By doing so, the base member and the support member can be assembled more reliably.

In the present invention, the cylindrical portion has a press-fitting end portion to be press-fitted into the circular hole, and a main body portion connected to the press-fitting end portion and having a diameter larger than that of the press-fitting end portion. It is preferable that the step portion between the main body portion and the main body portion is in contact with the base member. By doing so, the press-fit end portion can be press-fitted into the circular hole until the step portion between the press-fit end portion of the cylindrical portion and the main body portion abuts on the substrate member. Therefore, when a plurality of flow control valves are assembled, the press-fitting amount (dimension of the press-fitted portion) of the base member into the circular hole of the base member in the cylindrical portion of the support member can be made uniform.

In the present invention, the cylindrical portion has a press-fitting end portion to be press-fitted into the circular hole and a main body portion connected to the press-fitting end portion. It is preferable that a protruding portion protruding outward in the radial direction from the press-fit end portion is provided, and the protruding portion is in contact with the base member. By doing so, the press-fitting end portion can be press-fitted into the circular hole until the protruding portion of the cylindrical portion abuts on the substrate member. Therefore, when a plurality of flow control valves are assembled, the amount of press-fitting into the circular hole of the base member in the cylindrical portion of the support member can be made uniform.

In the present invention, the support member has a fitting portion to be fitted inside the outer cylinder member, and the outer peripheral surface of the fitting portion is formed so as to be in contact with the inner peripheral surface of the outer cylinder member. Is preferable. By doing so, when the cylindrical portion of the support member is press-fitted into the circular hole of the base member, the outer peripheral surface of the fitting portion of the support member comes into contact with the inner peripheral surface of the outer cylinder member, and the press-fitting direction of the support member Can guide you to move to. Therefore, it is possible to prevent the cylindrical portion from being tilted toward the circular hole and press-fitted.

In the present invention, it is preferable that the support member has a contact portion that comes into contact with the end face at the other end of the outer cylinder member. By doing so, the cylindrical portion can be press-fitted into the circular hole until the contact portion of the support member abuts on the end face at the other end of the outer cylinder member. Therefore, when a plurality of flow control valves are assembled, the amount of press-fitting into the circular hole of the base member in the cylindrical portion of the support member can be made uniform.

In the present invention, the flow rate control valve further has a valve body drive unit including the drive shaft, and the support member is arranged inside the case of the valve body drive unit and the outer cylinder member, and the case and the case. It is preferable that the outer cylinder member is welded. By doing so, the case and the outer cylinder member are directly welded, and the number of welded parts is reduced as compared with the configuration in which the case and the outer cylinder member of the valve body drive portion are individually welded to the support member. be able to.

In the present invention, it is preferable that the outer cylinder member and the support member are fixed in a state where the end surface at the other end of the outer cylinder member is in contact with the support member. By doing so, when a plurality of flow control valves are assembled, the amount of press-fitting into the circular hole of the base member in the cylindrical portion of the support member can be made uniform.

In order to achieve the above object, a method for assembling a flow control valve according to another aspect of the present invention includes a valve chamber, a base member provided with a valve opening opening in the valve chamber, and a base member outside the base member. An arranged outer cylinder member, a valve body arranged to face the valve port and open / close the valve port, a drive shaft provided with the valve body at the tip portion, and the drive shaft as the valve port. The base member has a support member that movably supports the valve body in a direction facing the valve body, and the base member has a flow path connected to the valve port and a pressure equalizing hole connecting the flow path and the outside of the base member. Is a method for assembling a flow control valve provided with the above, wherein one end of the outer cylinder member is closed with the base member, and the support is provided in a circular hole arranged coaxially with the valve port provided in the base member. A cylindrical portion provided on the member and arranged coaxially with the drive shaft is press-fitted, and the cylindrical portion is press-fitted until the other end of the outer cylinder member abuts on the support member to press-fit the other end of the outer cylinder member. By closing with the support member, a back pressure chamber partitioned from the valve chamber is formed on the outside of the base member, and the valve body or the drive shaft is arranged so as to straddle the valve chamber and the back pressure chamber. It is characterized by doing.

According to the present invention, one end of the outer cylinder member is closed with the base member. A cylindrical portion arranged coaxially with the drive shaft provided on the support member is press-fitted into the circular hole coaxially arranged with the valve port provided on the base member. By pressing the cylindrical portion until the other end of the outer cylinder member abuts against the support member and closing the other end of the outer cylinder member with the support member, a back pressure chamber separated from the valve chamber is formed on the outside of the base member. At the same time, the valve body or the drive shaft is arranged so as to straddle the valve chamber and the back pressure chamber. By doing so, the cylindrical portion of the support member is press-fitted into the circular hole of the base member, and the base member and the support member are directly assembled, so that the valve port and the valve body are misaligned with a relatively simple structure. Can be effectively suppressed. Further, since the cylindrical portion is press-fitted into the circular hole, the base member and the support member can be assembled more reliably. Further, by pressing the cylindrical portion until the other end of the outer cylinder member abuts against the support member and closing the other end of the outer cylinder member with the support member, the cylinder of the support member is formed when a plurality of flow control valves are assembled. The amount of press-fitting of the substrate member into the circular hole in the portion can be made uniform.

According to the present invention, the differential pressure applied to the valve body in the moving direction can be effectively reduced without restricting the shape of the valve body.

It is a vertical sectional view (valve open state) of the flow rate control valve which concerns on 1st Example of this invention. It is a vertical cross-sectional view (valve closed state) of the flow rate control valve of FIG. It is an enlarged sectional view of the valve body of the flow control valve of FIG. 1 and the vicinity thereof. It is a vertical cross-sectional view (valve open state) which shows the structure of the modification of the flow rate control valve of FIG. It is a vertical cross-sectional view (valve closed state) which shows the structure of the modification of the flow rate control valve of FIG. It is an enlarged sectional view of the valve body of the flow rate control valve which concerns on 2nd Embodiment of this invention, and the vicinity thereof. It is an enlarged sectional view of the valve body of the flow control valve which concerns on 3rd Example of this invention, and the vicinity thereof.

(First Example)
Hereinafter, the flow rate control valve according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

1 and 2 are vertical cross-sectional views (valve open state, valve closed state) of the flow rate control valve according to the first embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of the valve body of the flow control valve of FIG. 1 and its vicinity. 4 and 5 are vertical cross-sectional views (valve open state, valve closed state) showing the configuration of a modified example of the flow control valve of FIG.

The flow rate control valve 1 of this embodiment is an electric valve used for adjusting the flow rate of the refrigerant in, for example, a refrigeration cycle.

The flow rate control valve 1 has a valve body 5, a valve body 6, and a valve body driving unit 8.

The valve body 5 has a base member 10 and an outer cylinder member 20.

The base member 10 is made of, for example, a stainless steel material. The base member 10 is formed in a bottomed cylindrical shape as a whole. The base member 10 integrally has a substantially cylindrical base main body 11 and a bottom wall 12 provided at the lower end of the base main body 11.

The base body 11 is provided with a valve chamber 13 which is a columnar space. The substrate main body 11 is provided with a circular hole 14 as a positioning hole that opens upward. The circular hole 14 is connected to the valve chamber 13. In this embodiment, the diameter of the valve chamber 13 and the diameter of the circular hole 14 are the same.

On the bottom wall 12, a circular valve port 15 that opens into the valve chamber 13, a flow path 16 that is connected to the valve port 15 and extends downward, a pressure equalizing hole 17 that extends laterally from the flow path 16, and a valve port 15 are provided. A valve seat 18 and a surrounding valve seat 18 are provided. The valve port 15 and the flow path 16 are provided so as to have a smaller diameter than the valve chamber 13 and be coaxial with the valve chamber 13. The pressure equalizing hole 17 connects the flow path 16 and the back pressure chamber 23, which will be described later, formed on the outside of the substrate member 10. The valve body 6 is seated on the valve seat 18.

The outer cylinder member 20 is made of, for example, a stainless steel material and is formed in a cylindrical shape. The outer cylinder member 20 is arranged outside the base member 10, and accommodates the base member 10 inside. The bottom wall 12 of the base member 10 is fitted into the lower end 20a, which is one end of the outer cylinder member 20, and the lower end 20a is closed by the base member 10. The lower end 20a of the outer cylinder member 20 is brazed to the bottom wall 12.

The valve body 5 has a first conduit 26 that penetrates the outer cylinder member 20 and the base body 11 from the lateral direction and is connected to the valve chamber 13. The first conduit 26 is brazed to the outer cylinder member 20. Further, the valve body 5 has a second conduit 27 connected to the flow path 16 of the substrate body 11. The second conduit 27 is brazed to the bottom wall 12 of the base body 11.

The valve body 6 is made of, for example, a stainless steel material. The valve body 6 is formed in a solid (that is, not hollow) columnar shape as a whole, and has a substantially conical shape facing downward at the lower end. The valve body 6 includes a columnar body portion 31, a substantially conical tip portion 32 provided at the lower end of the body portion 31, and an annular projecting portion 33 projecting laterally from the lower end of the body portion 31. , Are integrated. A mounting hole 31b is provided on the upper end surface 31a of the body portion 31. The tip protrusion 64e of the tip 64c of the drive shaft 64, which will be described later, is fitted into the mounting hole 31b. As a result, the valve body 6 is provided at the tip end portion 64c of the drive shaft 64. The body portion 31 is provided with a lateral hole 31c that penetrates laterally from the mounting hole 31b. The lateral hole 31c makes the fluid pressure inside the mounting hole 31b the same as the fluid pressure outside the valve body 6 to prevent the tip protrusion 64e from coming out of the mounting hole 31b.

The valve body 6 is arranged in the valve chamber 13 so as to face the valve port 15 in the vertical direction. The valve body 6 is moved in the vertical direction by the valve body driving unit 8 to open and close the valve port 15. The vertical direction is a direction in which the valve port 15 and the valve body 6 face each other, and is a moving direction of the valve body 6. When the valve body 6 is separated from the valve seat 18, the valve opening 15 is opened and the valve is opened. In the valve open state, the first conduit 26 and the second vessel 27 are connected via the valve chamber 13. When the valve body 6 comes into contact with (seats) the valve seat 18, the valve opening 15 closes and the valve is closed. In the valve closed state, the first conduit 26 and the second vessel 27 are shut off.

Since the tip portion 32 of the valve body 6 has a solid structure, there are no restrictions on the shape of the tip portion 32. Therefore, for the shape of the tip portion 32 of the valve body 6, a shape designed so as to obtain an equal percent characteristic or a characteristic close to the flow rate characteristic can be adopted. As such a shape, for example, there is a shape having an ellipsoidal surface or a plurality of conical tapered surface portions. The taper angle of the multi-stage conical tapered surface portion gradually increases as it approaches the valve port 15 side so as to imitate an ellipsoidal surface. Alternatively, a shape designed so that a linear characteristic can be obtained as a flow rate characteristic can be adopted as the shape of the tip portion 32 of the valve body 6.

The valve body driving unit 8 is attached to the upper part of the valve body 5. The valve body driving unit 8 moves the valve body 6 in the vertical direction to bring it into contact with and separate from the valve seat 18, and closes or opens the valve opening 15. The valve body drive unit 8 includes a can 40 as a case, a motor unit 50, a drive mechanism unit 60, and a holder 70.

The can 40 is made of, for example, a stainless steel material. The can 40 is formed in a cylindrical shape with the upper end closed. A holder 70 (specifically, a holder body 71) described later is fitted in the lower end 40a of the can 40, and the lower end 40a is closed by the holder 70. The lower end 40a of the can 40 is welded to the holder 70.

The motor unit 50 has a rotor 51 rotatably housed inside the can 40 and a stator 52 arranged outside the can 40. The stator 52 is composed of a yoke 53, a bobbin 54, a stator coil 55, a resin mold cover 56, and the like. The rotor 51 and the stator 52 form a stepping motor.

The drive mechanism unit 60 includes a guide bush 61, a valve shaft holder 62, a stopper mechanism 63, a drive shaft 64, and a sealing member 65.

The guide bush 61 integrally has a cylindrical small diameter portion 61a and a cylindrical large diameter portion 61b coaxially connected to the lower end of the small diameter portion 61a. The inner diameter of the small diameter portion 61a and the inner diameter of the large diameter portion 61b are the same. A male screw 61c is provided on the outer peripheral surface of the small diameter portion 61a. The small diameter portion 61a is provided with a lateral hole 61d that penetrates in the lateral direction.

The valve shaft holder 62 is formed in a cylindrical shape with the upper end closed. The valve shaft holder 62 integrally has a cylindrical peripheral wall portion 62a and an upper wall portion 62b that closes the upper end of the peripheral wall portion 62a. On the inner peripheral surface of the peripheral wall portion 62a, a female screw 62c screwed with the male screw 61c of the guide bush 61 is provided. The upper wall portion 62b is integrally connected to the rotor 51 via a support ring 66 that is caulked and fixed to the upper wall portion 62b. Therefore, when the rotor 51 rotates, the valve shaft holder 62 also rotates. Then, when the valve shaft holder 62 rotates, the valve shaft holder 62 moves in the axial direction (vertical direction) of the guide bush 61 due to the feed screw action of the male screw 61c and the female screw 62c. A return spring 67 made of a coil spring is provided above the valve shaft holder 62 to facilitate re-screwing when the male screw 61c and the female screw 62c are unscrewed.

The stopper mechanism 63 has a lower stopper body 63a fixed to the guide bush 61 and an upper stopper body 63b fixed to the valve shaft holder 62. When the valve shaft holder 62 reaches the lower limit position, the stopper mechanism 63 causes the lower stopper body 63a and the upper stopper body 63b to abut against each other and restricts the movement of the valve shaft holder 62 with respect to the guide bush 61.

The drive shaft 64 is formed in a long columnar shape as a whole. The drive shaft 64 is inserted through the guide bush 61 and is arranged coaxially with the guide bush 61. The drive shaft 64 is integrally provided with an upper end portion 64a, a body portion 64b, and a tip portion 64c in this order from top to bottom. The upper end portion 64a is formed to have a smaller diameter than the body portion 64b, and is inserted into a through hole of the upper wall portion 62b of the valve shaft holder 62. A push nut 64d is fixed to the upper end portion 64a. The body portion 64b is supported by a guide bush 61 so as to be slidable in the vertical direction. A compression coil spring 68 that constantly pushes the drive shaft 64 downward is provided between the stepped portion of the upper end portion 64a and the body portion 64b and the upper wall portion 62b of the valve shaft holder 62. Since the push nut 64d and the compression coil spring 68 are provided, the drive shaft 64 moves in the vertical direction as the valve shaft holder 62 moves. The tip portion 64c is provided with a slender tip protrusion 64e that is fitted into a mounting hole 31b of the body portion 31 of the valve body 6. Further, the drive shaft 64 is integrally provided with a flange portion 64f protruding in the lateral direction at the lower end of the body portion 64b. The diameter of the flange portion 64f is the same as the diameter of the body portion 31 of the valve body 6.

The sealing member 65 is formed in an annular shape. The sealing member 65 is fitted with the tip 64c of the drive shaft 64 inside. That is, the sealing member 65 penetrates the tip portion 64c of the drive shaft 64. The sealing member 65 is arranged so as to be sandwiched between the flange portion 64f and the upper end surface 31a of the body portion 31 of the valve body 6. In this embodiment, the sealing member 65 is provided with a ring-shaped packing 65b made of polytetrafluoroethylene (PTFE) on the outside of an O-ring 65a made of a rubber material.

The holder 70 is made of, for example, a stainless steel material. The holder 70 integrally has a substantially disk-shaped holder main body 71 and a cylindrical portion 72 as a protrusion for positioning. The cylindrical portion 72 projects downward from the lower surface 71a of the holder main body 71.

The upper end 20b of the holder main body 71 is welded to the holder main body 71 in a state where the end surface 20c of the upper end 20b as the other end of the outer cylinder member 20 is in contact with the lower surface 71a. The upper end 20b of the outer cylinder member 20 is closed by the holder body 71. As a result, the back pressure chamber 23 partitioned from the valve chamber 13 is formed by the base member 10, the outer cylinder member 20, and the holder main body 71. Further, the lower end 40a of the can 40 is welded to the holder body 71.

A circular press-fit hole 71b arranged coaxially with the cylindrical portion 72 is provided in the center of the upper surface of the holder main body 71. The large diameter portion 61b of the guide bush 61 is press-fitted into the press-fit hole 71b. As a result, the holder body 71 and the guide bush 61 are integrated with the guide bush 61 and the cylindrical portion 72 coaxially arranged. The holder 70 and the guide bush 61 form a support member 69 that movably supports the drive shaft 64 in the direction opposite to the valve port 15 and the valve body 6. A shaft hole 71c through which the body portion 64b of the drive shaft 64 is inserted is provided in the center of the bottom surface of the press-fit hole 71b. A vertical hole 71d penetrating in the vertical direction is provided on the peripheral edge of the holder body 71.

The cylindrical portion 72 is press-fitted into the circular hole 14 of the base member 10. As a result, the holder 70 is directly assembled with the base member 10, and the cylindrical portion 72 and the circular hole 14 are coaxially arranged. The cylindrical portion 72 and the valve port 15 are also arranged coaxially. Further, by inserting the cylindrical portion 72 into the circular hole 14, the circular hole 14 restricts the movement of the cylindrical portion 72 in the direction orthogonal to the vertical direction (opposing direction).

Inside the cylindrical portion 72, the body portion 31 of the valve body 6, the tip portion 64c and the flange portion 64f of the drive shaft 64, and the sealing member 65 are arranged so as to be movable in the vertical direction. The packing 65b arranged on the outer periphery of the sealing member 65 is pressed against the inner surface of the cylindrical portion 72. As a result, the sealing member 65 seals between the valve chamber 13 and the back pressure chamber 23. As the drive shaft 64 moves in the vertical direction, the sealing member 65 is slid on the inner peripheral surface of the cylindrical portion 72. A lateral hole 72a penetrating in the lateral direction is provided at the upper end of the cylindrical portion 72. In this embodiment, the inner diameter of the cylindrical portion 72 (that is, the diameter of the sealing portion sealed by the sealing member 65) is the same as the diameter of the valve port 15. The inner diameter of the cylindrical portion 72 may be different from the diameter of the valve port 15, but it is preferable to reduce the difference between them.

In the flow control valve 1, since the valve chamber 13 and the back pressure chamber 23 are sealed by the sealing member 65 fitted in the tip portion 64c of the drive shaft 64, the drive shaft 64 has the valve chamber 13 and the back pressure. It is arranged so as to straddle the room 23. The flow path 16 of the base member 10 and the back pressure chamber 23 are connected by a pressure equalizing hole 17 of the base member 10. The back pressure chamber 23 and the inner space 41 of the can 40 are connected by a vertical hole 71d of the holder main body 71. Therefore, in the valve closed state, the fluid pressure in the flow path 16 and the fluid pressure in the back pressure chamber 23 are the same, and the fluid pressure applied to the valve body 6 from the valve port 15 side and the fluid pressure applied from the back pressure chamber 23 side. The difference (difference pressure) from is small. In this embodiment, the diameter of the valve port 15 (indicated by the double-headed arrow D1 in FIG. 3) and the inner diameter of the cylindrical portion 72 of the holder 70 (indicated by the double-headed arrow D2 in FIG. 3) are the same. Therefore, the differential pressure becomes zero (including almost zero), and it is possible to effectively suppress the movement of the valve body 6 from being hindered by the differential pressure.

The space 72b above the flange portion 64f inside the cylindrical portion 72 is connected to the back pressure chamber 23 by a lateral hole 72a. Further, the space 72b is also connected to the back pressure chamber 23 by the inner space 41 of the can 40, the lateral hole 61d of the guide bush 61, the gap between the guide bush 61 and the drive shaft 64, and the shaft hole 71c of the holder 70. .. As a result, even when the fluid pressure in the space 72b changes due to the movement of the flange portion 64f, the fluid pressure in the space 72b quickly becomes the same as the fluid pressure in the back pressure chamber 23.

Next, the method of assembling the flow rate control valve 1 described above will be described.

(1) Assemble the valve body 5. Specifically, the base member 10 is fitted into the lower end 20a of the outer cylinder member 20 to close the lower end 20a. The first conduit 26 is fitted into the outer cylinder member 20 and the base body 11 of the base member 10. The second conduit 27 is fitted into the bottom wall 12 of the base member 10. Then, brazing is performed by installing a brazing material at each brazing location and putting it into a furnace.

(2) Assemble the valve body drive unit 8. Specifically, the large diameter portion 61b of the guide bush 61 is press-fitted into the press-fit hole 71b of the holder body 71 to integrate the holder body 71 and the guide bush 61. The female screw 62c of the valve shaft holder 62 is screwed into the male screw 61c of the guide bush 61. A lower stopper body 63a is attached to the guide bush 61 in advance. An upper stopper body 63b is attached to the valve shaft holder 62 in advance. Further, the rotor 51 is connected in advance to the valve shaft holder 62 via the support ring 66. The tip 64c of the drive shaft 64 is fitted into the sealing member 65, the tip protrusion 64e of the tip 64c is fitted into the mounting hole 31b of the valve body 6, and the valve body 6 is attached to the drive shaft 64. The drive shaft 64 is inserted into the cylindrical portion 72 of the holder 70, the shaft hole 71c of the holder 70, and the guide bush 61 from below. A compression coil spring 68 is installed at the upper end portion 64a of the drive shaft 64, and the upper end portion 64a is inserted into the through hole of the upper wall portion 62b of the valve shaft holder 62. A push nut 64d is fixed to the upper end portion 64a of the drive shaft 64, and a return spring 67 is arranged. Then, the assembly body to which the rotor 51, the guide bush 61, the valve shaft holder 62, the stopper mechanism 63, and the like are assembled is inserted into the can 40. The holder body 71 is fitted into the lower end 40a of the can 40, and the lower end 40a is closed by the holder body 71. The lower end 40a of the can 40 is welded to the holder body 71. The stator 52 is attached to the can 40. In this state, the drive shaft 64 and the valve body 6 are arranged coaxially with the cylindrical portion 72.

(3) Then, the valve body 5 and the valve body drive unit 8 are assembled. Specifically, the cylindrical portion 72 is press-fitted into the circular hole 14 of the base member 10. By pressing the cylindrical portion 72 until the end surface 20c of the upper end 20b of the outer cylinder member 20 comes into contact with the holder body 71 and closing the upper end 20b with the holder body 71, the valve chamber 13 is partitioned outside the base member 10. The back pressure chamber 23 is formed. At the same time, the drive shaft 64 is arranged so as to straddle the valve chamber 13 and the back pressure chamber 23. Finally, the upper end 20b of the outer cylinder member 20 is welded to the holder body 71. In this way, the flow control valve 1 is completed.

From the above, according to the flow rate control valve 1 of the present embodiment, the lower end 20a of the outer cylinder member 20 is closed by the base member 10, and the upper end 20b of the outer cylinder member 20 is closed by the holder body 71. , A back pressure chamber 23 partitioned from the valve chamber 13 is formed. The drive shaft 64 is arranged so as to straddle the valve chamber 13 and the back pressure chamber 23. The substrate member 10 is provided with a flow path 16 connected to the valve port 15 and a pressure equalizing hole 17 connecting the flow path 16 and the back pressure chamber 23. Therefore, the pressure equalizing hole 17 provided in the base member 10 allows the fluid pressure applied to the valve body 6 from the valve port 15 side and the fluid pressure applied from the back pressure chamber 23 side to the valve body 6 in the closed state. The difference between the two can be reduced. Therefore, the differential pressure applied to the valve body 6 in the moving direction can be effectively reduced without restricting the shape of the valve body 6.

Further, the flow control valve 1 is formed in an annular shape through which the drive shaft 64 penetrates, and has a sealing member 65 that seals between the valve chamber 13 and the back pressure chamber 23. The inner diameter of the cylindrical portion 72 (the diameter of the sealing portion sealed by the sealing member 65, which is indicated by the double-headed arrow D2 in FIG. 3) is the diameter of the valve port 15 (indicated by the double-headed arrow D1 in FIG. 3). Is the same as. By doing so, the difference between the fluid pressure applied from the valve port 15 side and the fluid pressure applied from the back pressure chamber 23 side to the valve body 6 can be made zero in the valve closed state. Therefore, the differential pressure applied to the valve body 6 in the moving direction can be reduced more effectively without restricting the shape of the valve body 6.

Further, the flow control valve 1 is provided with a circular hole 14 arranged coaxially with the valve port 15 in the base member 10, and a cylindrical portion 72 arranged coaxially with the drive shaft 64 in the holder 70. Then, the cylindrical portion 72 is press-fitted into the circular hole 14. By doing so, the base member 10 and the holder 70 can be directly assembled, and the axial deviation between the valve port 15 and the valve body 6 can be effectively suppressed with a relatively simple configuration. Further, the base member 10 and the holder 70 can be more reliably assembled by press fitting.

Further, the outer cylinder member 20 and the holder main body 71 are fixed by welding in a state where the end surface 20c of the upper end 20b of the outer cylinder member 20 is in contact with the holder main body 71. By doing so, when a plurality of flow control valves 1 are assembled, the amount of press-fitting of the base member 10 of the cylindrical portion 72 into the circular hole 14 can be made uniform.

In the above-described embodiment, the cylindrical portion 72 of the holder 70 is press-fitted into the circular hole 14 of the base member 10, but other configurations may be adopted. For example, a configuration may be adopted in which the cylindrical portion 72 is inserted into the circular hole 14, and a sealing member such as an O-ring is provided between the outer peripheral surface of the cylindrical portion 72 and the inner peripheral surface of the circular hole 14.

Further, in the above-described embodiment, the valve body 6 and the drive shaft 64 are formed separately, but for example, as in the flow control valve 1A shown in FIGS. 4 and 5, the valve body 6 and the drive shaft 64 are formed. And may be integrally configured. In this configuration, the valve body 6 includes the drive shaft 64, and the valve body 6 is arranged so as to straddle the valve chamber 13 and the back pressure chamber 23. Then, the sealing member 65 is formed in an annular shape through which the valve body 6 penetrates, and seals between the valve chamber 13 and the back pressure chamber 23.

Further, in the above-described embodiment, the base member 10 is provided with a circular hole 14 as a positioning hole, and the holder 70 is provided with a cylindrical portion 72 as a positioning protrusion. On the contrary, the base member 10 may be provided with a protrusion for positioning, and the holder 70 may be provided with a hole for positioning.

(Second Example)
Hereinafter, the flow rate control valve according to the second embodiment of the present invention will be described with reference to FIG.

FIG. 6 is an enlarged cross-sectional view of the valve body of the flow control valve according to the second embodiment of the present invention and its vicinity. In the flow rate control valve 2 according to the second embodiment shown in FIG. 6, the same components as those of the flow rate control valve 1 are designated by the same reference numerals, and the description thereof will be omitted.

The flow rate control valve 2 has a holder 70A having a different configuration from the holder 70 of the flow rate control valve 1.

The holder 70A is made of, for example, a stainless steel material. The holder 70A integrally has a substantially disk-shaped holder main body 71A and a cylindrical cylindrical portion 72A as a protrusion for positioning. The cylindrical portion 72A projects downward from the lower surface 71a of the holder body 71A.

The outer diameter of the holder body 71A is the same as the inner diameter of the outer cylinder member 20. The holder body 71A corresponds to a fitting portion and is fitted inside the upper end 20b of the outer cylinder member 20. The upper end 20b of the outer cylinder member 20 is closed by the holder body 71A. The holder 70A and the guide bush 61 form a support member 69A. The support member 69A is arranged inside the can 40 and the outer cylinder member 20. The lower end 40a of the can 40 is welded to the upper end 20b of the outer cylinder member 20. By directly welding the can 40 and the outer cylinder member 20, the number of welded parts can be reduced as compared with the flow control valve 1 of the first embodiment in which the can 40 and the outer cylinder member 20 are individually welded to the holder 70.

The cylindrical portion 72A has a press-fit end portion 72c which is a tip portion and a main body portion 72d. The press-fit end portion 72c and the main body portion 72d are connected in the vertical direction. The main body portion 72d is formed to have a diameter larger than that of the press-fit end portion 72c. A step portion 72e is formed between the press-fit end portion 72c and the main body portion 72d. The press-fit end portion 72c is press-fitted into the circular hole 14 until the step portion 72e abuts on the substrate member 10. As a result, the holder 70A is directly assembled with the base member 10, and the cylindrical portion 72A and the circular hole 14 (that is, the valve port 15) are coaxially arranged. Then, the circular hole 14 restricts the movement of the cylindrical portion 72A in the direction orthogonal to the vertical direction (opposing direction). Further, the step portion 72e of the cylindrical portion 72A is in contact with the base member 10. Therefore, when a plurality of flow control valves 2 are assembled, the amount of press-fitting of the base member 10 into the circular hole 14 in the cylindrical portion 72A can be made uniform.

Further, the holder body 71A is fitted inside the upper end 20b of the outer cylinder member 20. Since the outer diameter of the holder body 71A is the same as the inner diameter of the outer cylinder member 20, the outer peripheral surface of the holder body 71A is formed so as to be in contact with the inner peripheral surface of the outer cylinder member 20. As a result, when the press-fitting end 72c of the cylindrical portion 72A is press-fitted into the circular hole 14 of the base member 10, the outer peripheral surface of the holder body 71A comes into contact with the inner peripheral surface of the outer cylinder member 20 and is in the vertical direction (press-fitting direction). Guide you to move to. Therefore, it is possible to prevent the press-fitting end portion 72c of the cylindrical portion 72A from being tilted into the circular hole 14 and being press-fitted.

In this embodiment, the cylindrical portion 72A has a configuration in which a step portion 72e is provided between the press-fit end portion 72c and the main body portion 72d. In addition to this configuration, the following configuration may be adopted. That is, the cylindrical portion 72A has a press-fit end portion 72c which is a tip portion and a main body portion 72d which is connected to the press-fit end portion 72c. At the end of the main body 72d on the press-fit end 72c side, a protruding portion that protrudes radially outward from the press-fit end 72c is provided. For example, one or a plurality of protrusions are provided at intervals in the circumferential direction. Then, the protruding portion is in contact with the base member 10. Also in this configuration, the press-fitting end portion 72c is press-fitted into the circular hole 14 until the protruding portion abuts on the base member 10, so that when a plurality of flow control valves are assembled, the circular hole of the base member 10 in the cylindrical portion 72A is formed. The amount of press-fitting into 14 can be made uniform.

(Third Example)
Hereinafter, the flow rate control valve according to the third embodiment of the present invention will be described with reference to FIG. 7.

FIG. 7 is an enlarged cross-sectional view of the valve body of the flow control valve according to the third embodiment of the present invention and its vicinity. In the flow rate control valve 3 according to the third embodiment shown in FIG. 7, the same components as those of the flow rate control valve 1 are designated by the same reference numerals, and the description thereof will be omitted.

The flow rate control valve 3 has a holder 70B having a different configuration from the holder 70 of the flow rate control valve 1.

The holder 70B is made of, for example, a stainless steel material. The holder 70B integrally has a substantially disk-shaped holder main body 71B and a cylindrical portion 72B as a protrusion for positioning. The cylindrical portion 72B projects downward from the lower surface 71a of the holder body 71B.

The holder body 71B has a fitting portion 71e and a contact portion 71f. The fitting portion 71e is formed in a columnar shape, and the outer diameter is the same as the inner diameter of the outer cylinder member 20. The fitting portion 71e is fitted inside the upper end 20b of the outer cylinder member 20. The contact portion 71f is an annular protrusion provided at the upper end of the outer peripheral surface of the fitting portion 71e so as to project outward in the radial direction. The contact portion 71f is formed so that the outer diameter is the same as the inner diameter of the can 40. The contact portion 71f is in contact with the end surface 20c of the upper end 20b of the outer cylinder member 20. The upper end 20b of the outer cylinder member 20 is closed by the holder body 71B. The holder 70B and the guide bush 61 form a support member 69B. The support member 69B is arranged inside the can 40 and the outer cylinder member 20. The lower end 40a of the can 40 is welded to the upper end 20b of the outer cylinder member 20.

The cylindrical portion 72B is press-fitted into the circular hole 14 of the base member 10. Then, the contact portion 71f of the holder body 71B is in contact with the end surface 20c of the upper end 20b of the outer cylinder member 20. Therefore, when a plurality of flow control valves 3 are assembled, the amount of press-fitting of the base member 10 into the circular hole 14 in the cylindrical portion 72B can be made uniform.

Further, the fitting portion 71e of the holder body 71B is fitted inside the upper end 20b of the outer cylinder member 20. Since the outer diameter of the fitting portion 71e is the same as the inner diameter of the outer cylinder member 20, the outer peripheral surface of the fitting portion 71e is formed so as to be in contact with the inner peripheral surface of the outer cylinder member 20. As a result, when the cylindrical portion 72B is press-fitted into the circular hole 14 of the base member 10, the outer peripheral surface of the fitting portion 71e comes into contact with the inner peripheral surface of the outer cylinder member 20 and moves in the vertical direction (press-fitting direction). invite. Therefore, it is possible to prevent the cylindrical portion 72B from being tilted and press-fitted into the circular hole 14.

Although examples of the present invention have been described above, the present invention is not limited to these examples. As long as the gist of the present invention is not contrary to the above-described embodiment, those skilled in the art appropriately adding, deleting, or changing the design, or combining the features of the examples as appropriate are also present inventions. Is included in the range of.

(First Example)
1, 1A ... Flow control valve, 5 ... Valve body, 6 ... Valve body, 8 ... Valve body drive unit, 10 ... Base member, 11 ... Base body, 12 ... Bottom wall, 13 ... Valve chamber, 14 ... Circular hole, 15 ... Valve port, 16 ... Flow path, 17 ... Pressure equalizing hole, 18 ... Valve seat, 20 ... Outer cylinder member, 20a ... Lower end, 20b ... Upper end, 23 ... Back pressure chamber, 26 ... First conduit, 27 ... No. 2 conduits, 31 ... body, 31a ... upper end surface, 31b ... mounting hole, 31c ... horizontal hole, 32 ... tip, 33 ... annular protrusion, 40 ... can, 40a ... lower end, 41 ... inner space, 50 ... motor Part, 51 ... rotor, 52 ... stator, 53 ... yoke, 54 ... bobbin, 55 ... stator coil, 56 ... resin mold cover, 60 ... drive mechanism part, 61 ... guide bush, 61a ... small diameter part, 61b ... large diameter part , 61c ... Male screw, 61d ... Horizontal hole, 62 ... Valve shaft holder, 62a ... Peripheral wall part, 62b ... Upper wall part, 62c ... Female screw, 63 ... Stopper mechanism, 63a ... Lower stopper body, 63b ... Upper stopper body, 64 ... Drive shaft, 64a ... upper end, 64b ... body, 64c ... tip, 64d ... push nut, 64e ... tip protrusion, 64f ... flange, 65 ... sealing member, 65a ... O-ring, 65b ... packing, 66 ... Support ring, 67 ... Return spring, 68 ... Compression coil spring, 69 ... Support member, 70 ... Holder, 71 ... Holder body, 71a ... Bottom surface, 71b ... Press-fit hole, 71c ... Shaft hole, 71d ... Vertical hole, 72 ... Cylindrical Part, 72a ... Horizontal hole,
(Second Example)
2 ... Flow control valve, 69A ... Support member, 70A ... Holder, 71A ... Holder body, 72A ... Cylindrical part, 72c ... Press-fit end part, 72d ... Main body part, 72e ... Step part,
(Third Example)
3 ... Flow control valve, 69B ... Support member, 70B ... Holder, 71B ... Holder body, 72B ... Cylindrical part, 71e ... Fitting part, 71f ... Contact part

Claims (12)

A base member provided with a valve chamber and a valve opening that opens into the valve chamber, and a base member.
An outer cylinder member arranged outside the base member and
A valve body that is arranged to face the valve opening and opens and closes the valve opening,
The drive shaft provided with the valve body at the tip and
It has a support member that movably supports the drive shaft in a direction opposite to the valve port and the valve body.
One end of the outer cylinder member is closed by the base member, and the other end of the outer cylinder member is closed by the support member, forming a back pressure chamber partitioned from the valve chamber.
The valve body or the drive shaft is arranged so as to straddle the valve chamber and the back pressure chamber.
The base member is a flow rate control valve provided with a flow path connected to the valve port and a pressure equalizing hole connecting the flow path and the back pressure chamber. It has a sealing member formed in an annular shape through which the valve body or the drive shaft penetrates and seals between the valve chamber and the back pressure chamber.
The flow rate control valve according to claim 1, wherein the diameter of the sealing portion sealed by the sealing member is the same as the diameter of the valve port. A protrusion is provided on one of the base member and the support member, and a hole is provided on the other side through which the protrusion is inserted to regulate the movement of the protrusion in a direction orthogonal to the facing direction. The flow rate control valve according to claim 1 or 2. The substrate member is provided with a circular hole arranged coaxially with the valve port as the hole.
The flow rate control valve according to claim 3, wherein the support member is provided with a cylindrical portion arranged coaxially with the drive shaft as the protrusion. The flow rate control valve according to claim 4, wherein the cylindrical portion is press-fitted into the circular hole. The cylindrical portion has a press-fitting end portion to be press-fitted into the circular hole, and a main body portion connected to the press-fitting end portion and having a diameter larger than that of the press-fitting end portion.
The flow rate control valve according to claim 5, wherein a step portion between the press-fitting end portion and the main body portion is in contact with the base member. The cylindrical portion has a press-fit end portion that is press-fitted into the circular hole and a main body portion that is connected to the press-fit end portion.
At the end of the main body on the press-fitting end side, a protruding portion that protrudes radially outward from the press-fitting end is provided.
The flow rate control valve according to claim 5, wherein the protruding portion is in contact with the base member. The support member has a fitting portion that is fitted inside the outer cylinder member.
The flow rate control valve according to any one of claims 5 to 7, wherein the outer peripheral surface of the fitting portion is formed so as to be in contact with the inner peripheral surface of the outer cylinder member. The flow rate control valve according to claim 5, wherein the support member has a contact portion that comes into contact with an end surface at the other end of the outer cylinder member. Further having a valve body drive unit including the drive shaft,
The support member is arranged inside the case of the valve body drive unit and the outer cylinder member.
The flow rate control valve according to any one of claims 5 to 9, wherein the case and the outer cylinder member are welded to each other. The flow rate control valve according to claim 5, wherein the outer cylinder member and the support member are fixed in a state where the end surface at the other end of the outer cylinder member is in contact with the support member. A valve chamber, a base member provided with a valve opening that opens into the valve chamber, an outer cylinder member arranged outside the base member, and a valve that is arranged to face the valve opening and opens and closes the valve opening. The base member includes a body, a drive shaft provided at the tip of the valve body, and a support member that movably supports the drive shaft in a direction opposite to the valve port and the valve body. A method for assembling a flow control valve provided with a flow path connected to the valve port and a pressure equalizing hole for connecting the flow path and the outside of the base member.
One end of the outer cylinder member is closed with the base member,
A cylindrical portion provided coaxially with the drive shaft provided on the support member is press-fitted into a circular hole coaxially arranged with the valve port provided on the base member.
By pressing the cylindrical portion until the other end of the outer cylinder member abuts against the support member and closing the other end of the outer cylinder member with the support member, the valve chamber is partitioned on the outside of the base member. A method for assembling a flow control valve, which comprises forming a back pressure chamber and arranging the valve body or the drive shaft so as to straddle the valve chamber and the back pressure chamber.

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